Article Text

Download PDFPDF

Impact of Ramadan fasting on glucose levels in women with gestational diabetes mellitus treated with diet alone or diet plus metformin: a continuous glucose monitoring study
  1. Bachar O Afandi1,
  2. Mohamed M Hassanein2,
  3. Lina M Majd1,
  4. Nico J D Nagelkerke3
  1. 1Endocrine Diabetes Center, Tawam Hospital/SEHA, Al Ain, Abu Dhabi, UAE
  2. 2Department of Endocrine, Dubai Hospital, DHA, Dubai, Dubai, UAE
  3. 3Medicine, Institute of Public Health, UAE University, Al Ain, Abu Dhabi, UAE
  1. Correspondence to Dr Bachar O Afandi, Tawam Hospital; bafandi{at}


Objective Women with gestational diabetes mellitus (GDM) are categorized as at high risk for adverse events during Ramadan fasting. However, this is largely based on clinical opinion. In this study, we shed some light on what happens to glucose levels during Ramadan fasting.

Methods This is a prospective observational study. A total of 32 patients with GDM were recruited; 10 patients, treated with diet only (group 1), to observe their glucose levels before fasting and 22 patients who insisted on fasting the month of Ramadan, 13 treated with diet only (group 2) and nine treated with diet plus metformin 500 mg twice daily (group 3), to evaluate their glucose levels during fasting. Interstitial glucose was monitored in all by using the iPro2 Professional continuous glucose monitoring (CGM) system.

Results Mean glucose level was 116±21 mg/dL (6.16±1.16 mmol/L), 106±9 mg/dL (5.88±0.49 mmol/L) and 99±7 mg/dL (5.49±0.34 mmol/L) in groups 1, 2 and 3, respectively. Patients in group 1 had the lowest rate of hypoglycemia (50%), followed by patients in group 2 (60%), whereas patients in group 3 had the highest rate of hypoglycemia (78%).

Conclusions CGM data indicates that Ramadan fasting in women with GDM treated with diet alone or with diet plus metformin was associated with lower mean glucose levels and higher rates of hypoglycemia when compared with non-fasting glucose levels. Women with GDM should be advised against fasting during Ramadan until further data is available.

  • fasting
  • continuous glucose monitoring
  • gestational diabetes mellitus
  • hypoglycemia

This is an Open Access article distributed in accordance with the Creative Commons Attribution Non Commercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See:

Statistics from

Request Permissions

If you wish to reuse any or all of this article please use the link below which will take you to the Copyright Clearance Center’s RightsLink service. You will be able to get a quick price and instant permission to reuse the content in many different ways.


  • Contributors BOA planned and submitted the study for approval, researched data, wrote and edited the manuscript. MH planned the study, researched data, wrote and edited the manuscript. LM recruited and followed patients, obtained consents, contributed to discussion. NN analysed the data and edited the manuscript. BA takes full responsibility for the work. The authors have no relevant conflict of interest to disclose.

  • Funding This research received no specific grant from any funding agency in the public, commercial or not-for-profit sectors.

  • Competing interests None declared.

  • Ethics approval Al-Ain Medical District Human Research and Ethics Committee (CRD517/17 Protocol NO 17-46).

  • Provenance and peer review Not commissioned; externally peer reviewed.

  • Data sharing statement This material has not been published previously and is not under consideration for publication elsewhere.